I've done a fair amount of wood working but wouldn't consider myself a pro and there is no way I would do those joints! lol From what I understand, and correct me if I'm wrong, y'all, but those can be tricky and difficult to match up, especially if you don't have the proper equipment to make it easy. If I were you, I'd start out with simple corners and build a couple and then if it really suits you and you enjoy it, move on to the more difficult working corners. If it's a humi, it has to be perfect for the seal, etc. Just my
Good luck!